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A member of another Forum posed the question "Does fitment of a non OE turbo reduce the life of the engine".
A couple of posts said "No - no problems".
I have always been of the impression that a non-OE turbo fitment (unless low boost) would put a lot more strain on the components.
Maybe I have had it wrong all this time. We have some experts on here - what do they say?

Its like asking 'will jogging damage my body as opposed to walking?'

Well if you go jogging and twist your ankle the wrong way it sure will, but if you dont then youre only going to wear your knees out a bit quicker.

Even that's not true. Running strengthens your knees, legs and all sorts of other things. Running means improved longterm health.
Adding a turbo does not increase longetivity.

I referred only to ankles and knees. I think what i said is fair if taken as it was written. I apologise if knees dont get worn out joghing, I was under the impression they did.

Getting technical, any addition of power/torque, if used, will wear out the rings and ..maybe the bearings in some cases.. faster.

Outside of that its up to the setup/tune. Get it right and youre only wearing out some components a little quicker if you use the performance regularly. The same goes for oem turbo vs oem n/a models. Minor additional wear on the parts affected.

I'd assume it would be fair to say that an SE or SP turbo setup engine will wear faster than a non-turbo NB motor, even though they're both OE supplied by Mazda.

I wonder what the wear rate differences would be between an OE MX-5 turbo (SE/SP) vs an aftermarket setup such as Dann's twistmount? The stock OE would last longer I'd think, but if they were modded to a similar level/quality (like my SE) I wonder which would last longer? My thinking is there wouldn't be much in it and it would come down to individual driving style/uses than to the setup components.

Were any parts even upgraded/strengthened in the SE engine or was it considered unnecessary with the small turbo.

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Different pistons for a lower CR I think. A different intake cam. That's it for the motor as far as I know.

Supposedly the gearbox is stronger though I've seen no proof and the axles are bigger and stronger.

Internally, they lowered the compression. This isnt necessary all of the time to add a turbo, however the se turbo setup is so tiny and inefficient that it is detonation prone even with the lower compression.

For instance, total ignition timing on a NB2 TwistMount2 package is similar to that of an SE with full bolt ons despite making 50whp more and being 10:1 rather than 9:1 static compression.

This is due mostly to significantly lower exhaust backpressure, in my opinion.

Dann

Following up, the weakest link inside the B series engine in terms of failure via power/torque is the conrods. The conrods used are identical from the 121 'bubble' 1.3L engine all the way to SE and SP.

This means that all of these engine are capable of making 220ftlb or so reliably. The difference will be how much the cylinder head flows and therefor how much boost pressure will be required to push the 220ftlb worth of air past the valves and into the engine.

How much power you can make with 220ftlb will depend on the rate at which you can repeatedly make 220ftlb. Ie. The RPM.

220ftlb at 7200 rpm is 300hp. (Yes, at the wheels!)

The struggle is has been picking a turbocharger which is responsive enough to make 220ftlb worth of boost pressure at 7200rpm. Ie a turbo which can make 300whp on a standard cylinder head and not be laggy. These days its not hard and they are available, but no I won't warrant a 300whp setup if you ask for one on a stock motor.

We use a GT2860rs with the larger 0.86 rear housing. This means that exhaust backpressure is minimal and the setup is efficient. We run them at 200 ftlb for 260 or 270rwhp.

Its a misconception that a small oem turbo is easier on the engine. What breaks it is torque not power, and if a small turbo is good at anything it's spooling tonnes of boost up at low rpm and producing torque.

Dann

That's a great explanation, thanks Dann.

My pleasure.

I welcome any more questions also.

Dann

NitroDann wrote:My pleasure.

I welcome any more questions also.

Dann

I'm at ~175k km now, I run the E85 tune full time (250whp), daily driving though so I rarely push it hard for long. How much longer will my engine live? Which will go first, the motor or the turbo?

I realise that's not really something you or anyone can answer with certainty, I ask mostly in jest. But it's only a mater of time, so I'll need to start preparing rebuild funds.

I don't need more power, but I do want it

The turbo. Total engine life.. who knows. Weve had such an incredibly low failure rate that i am happy to call it close enough to oem given the use. Some of these 200kw cars have nearly 50,000 on them with dozens of track days. One has been written off twice and still hauls arse.

Of course there would have to be some problem cars ive simply never been told about, but for the most part id say theyre well proven now and my guess is youll get 250, but the turbo will blow beforehand.

250 was my guess/hope/goal. Turbo first, eh? I guess pushing up to 15psi through that tiny, crappy, inefficient IHI isn't doing it any favours! Let's see if I can get the turbo to 200, then I'll get serious on replacing it. I reckon that gives me about 18 months to get some funds (and not blow it on other mods), maybe 2 years...

Thanks for the input, Dann.